During showering, soap scum accumulates on glass shower doors. Soap scum consists of water-insoluble materials (calcium stearate and magnesium stearate) that are formed when calcium and magnesium ions in hard water react with soap. In addition, during and after showering when the warmer moisture in the air condenses on the cooler surface of glass shower doors or bathroom mirrors, water will bead-up on these surfaces, and steam or moisture will condense into water, thus preventing a clear, fog-free vision through glass shower doors and bathroom mirrors. Water vapor condenses on glass shower doors and bathroom mirrors when the temperature of the air adjacent to these surfaces falls below the dew-point. The dew-point is the temperature at which air reaches saturation, and water vapor condenses into liquid water often as an opaque or translucent thin film, thus leading to foggy glass shower doors and bathroom mirrors. The cleaning, scrubbing and removal of soap scum is time-consuming and costly, and the dissipation of water condensed on glass shower doors and bathroom mirrors can be slow or may not occur under foggy conditions. Thus efficiently preventing water from beading up and allowing it to sheet off of glass shower doors, to prevent both the adherence of soap scum as well as the condensation of water on glass bathroom surfaces, is an essential condition for transparent glass shower doors and bathroom mirrors to have utility. Water sheets off of glass shower doors when hydrophilic ingredients in a liquid formulation applied to these doors lower the surface tension of water and prevent it from beading up on the glass shower door surface and depositing and accumulating soap scum.
Disclosed claims for both cleaning glass surfaces and defogging mirrors are limited to formulations that include petrochemical, flammable, volatile organic compounds (VOC), or toxic or hazardous ingredients. The present invention relates to addressing these limitations and meeting the need for a biobased, non-toxic, biodegradable, aqueous liquid formulation free of VOC and a method for dispensing formulation for sheeting water off of glass shower doors during showering and preventing the deposition and accumulation of water-insoluble soap scum, for preventing glass shower doors and bathroom mirrors from fogging, and for cleaning said surfaces.
For many decades formulations of some all-purpose liquid detergents for cleaning hard surfaces such as bathtubs, tiled walls and floors, painted panels, glass surfaces, etc., which also exhibit anti-fogging properties, have incorporated among their ingredients harmful chemicals. For example, the formulation disclosed in U.S. Pat. No. WO1996003491A1 contains a cosurfactant with functional groups including diethylphosphate that is considered hazardous by the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200). It also contains the anionic surfactant alkyl benzene sulfonate which is corrosive, and may cause skin or eye burns as well as irritation to digestive and respiratory tracts. Pat. No. US005716921A discloses formulations containing toxic quaternary ammonium cationic surfactants, and those of U.S. Pat. No. 5,254,284A contain silicone glycol that is harmful if inhaled or absorbed through the skin. Good cleaning products do not necessarily enhance their antifogging efficacy and typically contain harsh, toxic, or synthetic chemicals, and extreme caution needs to be exercised when using them in order to minimize contact with human skin. Even at low concentrations, these aggressive chemicals can defat dermal oils.
Antifog formulations have also been disclosed in the literature. For instance, in U.S. Pat. No. 4,615,738, a transparent antifog composition is disclosed for nonporous substrates which comprise an aqueous solution of hexamethylcyclotrisiloxane, an aliphatic alcohol, and a surfactant. However, hexamethylcyclotrisiloxane is not recommended for institutional and household use because it is flammable and in laboratory animals it reportedly elicits hyperplasia and a chronic inflammatory response and leads to liver carcinogenesis.
Pat. No. US 2011/0098206 A1 discloses a hard surface treating composition that provides anti-fogging and cleaning benefits and includes among its ingredients a low percentage of VOC. However, exposure to toxic VOC, which are regulated by EPA and State regulatory agencies, is not recommended.
An increasing number of plant-based surfactants became available and used as ingredients in cleaning and other consumer or industrial products. They are alkyl polyglycosides (or alkyl polyglucosides) produced from renewable raw materials by reaction of glucose and fatty alcohol. The structure of an alkyl polyglycoside molecule consists of a hydrocarbon chain or tail that is hydrophobic consisting of a saturated fatty alcohol, such as dodecanol, derived from palm or coconut oil. The remaining hydrophilic portion of alkyl polyglycoside is derived from glucose or dextrose commonly obtained from corn starch. Plant-based surfactants are increasingly favored over those derived from petroleum because they help the industry comply with its sustainability goals by providing nature-based, biodegradable ingredients.
Accordingly, there is a need for developing a biobased, non-toxic, free of VOC, biodegradable, aqueous liquid formulation derived from natural and renewable sources that is available in stable, aqueous solution having a long shelf life, and available at an affordable price specifically for sheeting water off of glass shower doors during showering, for preventing in the first place the deposition and accumulation of soap scum, and for rendering treated bathroom glass surfaces resistant to fogging and clean. There is further a need for an effective, simple method for delivering by spraying every day or several days an anti-fog anti-soap scum liquid composition in sufficient amounts, thereby producing an adherent thin transparent film that dries after 10-20 seconds, yet leaving no visible residue, films, spots or streaks on treated glass shower doors and bathroom mirrors.